AZ-204 Develop Azure compute solutions Practice Question
A company uses Azure Functions to process messages from Azure Service Bus. The function currently uses the Consumption plan. They notice that during high load, messages are processed slowly due to scaling latency. Which change would improve throughput most?
⚠ Common exam trap
Candidates often assume increasing batch size or instance count will solve scaling latency, but they overlook that the fundamental issue is the cold start and provisioning delay inherent in the Consumption plan, which only the Premium plan resolves by providing pre-warmed instances and faster scaling.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Switch to the Premium plan
The Premium plan for Azure Functions provides pre-warmed instances and faster scaling, eliminating the cold start and scaling latency inherent in the Consumption plan. This directly addresses the bottleneck during high load by ensuring that new instances are allocated instantly, thereby improving message processing throughput from Service Bus.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Switch to the Premium plan
Why this is correct
Switching to the Premium plan directly addresses latency issues by providing pre-warmed instances, eliminating cold starts that often plague Consumption plan functions. This ensures that function apps are always ready to process messages immediately, leading to significantly faster response times and more predictable performance. Furthermore, Premium plans offer enhanced networking capabilities and dedicated resources, which contribute to more consistent and lower-latency message processing.
- ✗
Set the maximum instance count to 20
Why it's wrong here
Setting a maximum instance count to 20 limits the number of concurrent function instances that can process messages, which directly restricts the overall throughput capacity. While it can help manage costs, it does not improve the processing speed or reduce the latency for individual messages; instead, it can lead to message backlogs and increased end-to-end processing times if the message volume exceeds the limited concurrency.
- ✗
Increase the function's batch size to 100
Why it's wrong here
Increasing the function's batch size to 100 means a single function invocation will process more messages, which can increase the total execution time for that invocation. This can lead to higher latency for individual messages within the batch, potential timeouts if the processing exceeds the function's maximum execution duration, and may not improve overall throughput if the bottleneck is the per-message processing logic rather than invocation overhead.
- ✗
Enable Service Bus sessions
Why it's wrong here
Enabling Service Bus sessions is designed for ensuring ordered processing of related messages and maintaining state across a sequence of messages, not for improving general message processing speed or reducing latency. While critical for scenarios requiring FIFO guarantees or stateful interactions, sessions can actually limit concurrency within a given session, as messages must be processed sequentially, thus not addressing the core problem of overall processing latency.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
Go deeper
Related to this question
Learn chapter
Azure Functions Development
Key term
Durable Functions
Durable Functions is an extension of Azure Functions that lets you write stateful workflows in code, managing complex sequences of tasks, retries, and delays automatically.
Key term
Azure Service Bus
Azure Service Bus is a cloud-based message broker that allows applications, services, and devices to send and receive messages reliably, even when they are not all running at the same time.
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Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-204 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-204 exam.